Is Oak Harbor, OH Tap Water Safe? Quality & Contaminants

What was found in Oak Harbor's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

Contaminant	Level vs EPA limit	Suppliers	Source
Nitrate	3250 µg/L 33% of the EPA limit 10000 µg/L Highest in the city: CARROLL WATER AND SEWER · 2,288 people · 2019	1/2	SYR4
Nitrate-Nitrite	3250 µg/L 33% of the EPA limit 10000 µg/L Highest in the city: CARROLL WATER AND SEWER · 2,288 people · 2019	1/2	SYR4
Copper	235.95 µg/L 18% of the EPA limit 1300 µg/L Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2019 Highest in the city: 613.95 µg/L — CARROLL WATER AND SEWER · 2,288 people · 2019	2/2	SYR4
TTHM	87.65 µg/L 110% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2019 Highest in the city: 91.71 µg/L — CARROLL WATER AND SEWER · 2,288 people · 2019	2/2	SYR4
Chloroform	69.15 µg/L No EPA limit set Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2019 Highest in the city: 73.04 µg/L — CARROLL WATER AND SEWER · 2,288 people · 2019	2/2	SYR4
Total Haloacetic Acids (HAA5)	34.5 µg/L 57% of the EPA limit 60 µg/L Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2019 Highest in the city: 47.955 µg/L — CARROLL WATER AND SEWER · 2,288 people · 2019	2/2	SYR4
Lead	35.35 µg/L 236% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2019	2/2	SYR4
Barium	27 µg/L 1.4% of the EPA limit 2000 µg/L Highest in the city: CARROLL WATER AND SEWER · 2,288 people · 2019	1/2	SYR4
Trichloroacetic Acid	14.66 µg/L No EPA limit set Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2019 Highest in the city: 24.42 µg/L — CARROLL WATER AND SEWER · 2,288 people · 2019	2/2	SYR4
Dichloroacetic Acid	19.88 µg/L No EPA limit set Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2019 Highest in the city: 23.775 µg/L — CARROLL WATER AND SEWER · 2,288 people · 2019	2/2	SYR4
Bromodichloromethane	16.375 µg/L No EPA limit set Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2019 Highest in the city: 16.44 µg/L — CARROLL WATER AND SEWER · 2,288 people · 2019	2/2	SYR4
Dibromochloromethane	8.825 µg/L No EPA limit set Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2019	2/2	SYR4
Monochloroacetic Acid	4.66 µg/L No EPA limit set Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2019 Highest in the city: 8.52 µg/L — CARROLL WATER AND SEWER · 2,288 people · 2019	2/2	SYR4
Bromate	6 µg/L 60% of the EPA limit 10 µg/L Highest in the city: CARROLL WATER AND SEWER · 2,288 people · 2019	1/2	SYR4
Dibromoacetic Acid	2.9 µg/L No EPA limit set Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2019 Highest in the city: 3.545 µg/L — CARROLL WATER AND SEWER · 2,288 people · 2019	2/2	SYR4
Bromoform	1.645 µg/L No EPA limit set Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2019 Highest in the city: 1.77 µg/L — CARROLL WATER AND SEWER · 2,288 people · 2019	2/2	SYR4
Lead	0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: OAK HARBOR VILLAGE · 4,400 people · 2025	2/2	LCR

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of the system's samples — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Oak Harbor

Supplier	Population served
OAK HARBOR VILLAGE	4,400
CARROLL WATER AND SEWER	2,288

Frequently asked questions about Oak Harbor tap water

Is Oak Harbor tap water safe to drink?

EPA testing detected 17 contaminants in the water serving Oak Harbor. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Oak Harbor?

2 public water suppliers report drinking-water monitoring for Oak Harbor, Ohio to the EPA. Each is listed above with its population served.

What contaminants are in Oak Harbor's water?

The contaminants EPA monitoring detected in Oak Harbor include Nitrate, Nitrate-Nitrite, Copper, TTHM, Chloroform. The full list, with the level at the main supplier and the data source, is in the table above.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.